Apple Inc. indicated it would open its iTunes store to other portable players besides its ubiquitous iPod if the world’s major record labels abandoned the anti-piracy technology that serves as the industry’s security blanket.

Steve Jobs, Apple’s chief executive, made the case for abolishing the protections known as “Digital Rights Management,” or DRM, in an open letter posted Tuesday on the Cupertino, Calif.-based company’s Web site. He also explained why Apple had decided against licensing its own DRM technology, known as “FairPlay,” as an alternative method for making iTunes accessible to all portable players.